Writing a queue program

[Dmitriy78]

My professor is asking us to write a queue program, by which I mean that we are required to write out all of the functions of a queue like push, pop, etc. The program he asked us to write takes place in two .cpp files and one header file.

The professor provided some of the driver and the header files, but I still need to write the function itself, and add the code to a few functions on the driver. The header file is finished and cannot be modified. I wrote all of the necessary functions and the program does compile but I can't get it to do what it should.

Here is the code:

//The Header
const int MAX = 3;  //To do: determine appropriate number

struct Passenger {
char name[80];
};

class CQueue {
private:
int front;
int rear;
Passenger passengers[MAX];
 
public:
CQueue();
bool IsEmpty(void);
bool IsFull(void);
void Enqueue(Passenger);
Passenger Front(void);
void Dequeue(void); 
};
//The Functions:
#include "cqueue.h"
#include <cstring>
#include <iostream>
using namespace std;

CQueue::CQueue()
{
     for(int x=0;x<3;x++)
	 {
		 passengers[x].name==" ";
	 }
	 front=0;
	 rear=0;
}
bool CQueue::IsEmpty()
{
	for(int x=0;x<3;x++)
	{
		if(passengers[x].name!=" ")
		{
			return false;
		}
	}
	return true;
}
bool CQueue::IsFull()
{
	for(int x=0;x<3;x++)
	{
		if(passengers[x].name==" ")
		{
			return false;
		}
	}
	return true;
}
void CQueue::Enqueue(Passenger thePassenger)
{
	
	passengers[front]=thePassenger;
	if(front!=rear)
	{
		rear--;
	}
	front++;
	
	
}
Passenger CQueue::Front()
{
	cout<<"Outputting the passenger list: Booked Passengers:"<<endl;
	return passengers[1];
}
void CQueue::Dequeue()
{
	for(int x=0;x<3;x++)
	{
		passengers[x].name==" ";
	}
}
//The Driver:
#include <iostream>
#include <string>
#include <cstring>
#include "cqueue.h"
using namespace std;

enum choice { BOOKED, WAITING };
const int LINES = 2;
int showMenu(void);
void addPassenger(CQueue*);
void deletePassenger(CQueue*);
void showPassengers(CQueue*);

int main (void)
{
CQueue qPassengers[LINES];
int x;
do{
x = showMenu();
switch (x)
{
case 1: addPassenger(qPassengers);
break;
case 2: deletePassenger(qPassengers);
break;
case 3: showPassengers(qPassengers);
break;
}
} while (x != 4);
return 0;
}

int showMenu(void)
{
int select;

cout << "Menu\n";
cout << "========\n";
cout << "1. Add Passenger\n";
cout << "2. Delete Passenger\n";
cout << "3. Show Passengers\n";
cout << "4. Exit\n";
cout << "Enter choice: ";
cin >> select;
return select;
}
//void addPassenger(CQueue*);
//void deletePassenger(CQueue*);
//void showPassengers(CQueue*);
void addPassenger(CQueue *theQueue)
{
	Passenger theString;
if((theQueue[1].IsFull()==false) && (theQueue[2].IsFull()==false))
	 {
		cout<<"Both queues are full."<<endl;
	 }
else if(theQueue[1].IsEmpty()==false)
     {
		 cout<<"Please type in the name of the new passenger.";
		 cin>>theString.name;
		 theQueue[1].Enqueue(theString);
     }
else if((theQueue[1].IsEmpty())==true && (theQueue[1].IsFull())==true)
     {
		 cout<<"Please type in the name of the new passenger.";
		 cin>>theString.name;
		 theQueue[1].Enqueue(theString);
     }
else if(theQueue[2].IsEmpty()==false)
     {
		 cout<<"Please type in the name of the new passenger.";
		 cin>>theString.name;
		 theQueue[2].Enqueue(theString);
     }
else if((theQueue[2].IsEmpty())==true && (theQueue[2].IsFull())==true)
     {
		 cout<<"Please type in the name of the new passenger.";
		 cin>>theString.name;
		 theQueue[2].Enqueue(theString);
     }

}
void deletePassenger(CQueue *theQueue)
{
	theQueue[1].Dequeue();
}
void showPassengers(CQueue *theQueue)
{
	for(int x=1;x<=2;x++)
	{
		cout<<theQueue[1].Front().name;
	}
}

The way the program is supposed to work is to create two CQueue objects with one of them as a list of passengers on the plane and one as a waiting list. If the plane is full, passengers go on the waiting list (which also has a limit).

When I try to make the program show passengers it doesn't work (outputs a huge amount of random characters) and because of this I can't really tell if add or delete passengers works.

[oonej]

with a queue, if i remember correctly it doesn't always start from index [1]..

you should have 2 indices which point to the front and the back of the queue.

so you would start from the front of the queue theQueue[front] and increment it till front <= back;

[viliml]

void showPassengers(CQueue *theQueue)
{
	for(int x=1;x<=2;x++)
	{
		cout<<theQueue[1].Front().name;
	}
}

WHAT THE???

for(int x=1;x<=2;x++)

Maybe would have been useful if you used x anythere, but this is pure lazyness.

cout<<theQueue[1].Front().name;

You print the same thing 2 times! What's the point of that??